Improvement



'1'. P. SHAFFNER Artillery Mining and Blasting.

Patented Dec. 18, 1866.

I 11 i maxi v 2 Sheets-Sheet 1 2 Sheets fiSheet 2. 'l. P. SHAFFNER. Artillery Mining and Blasting.

- Patented Dec. 18, 1866.

rock, coal, earth,

' used nitroleum TAL. r. snarrnna, or tooisvrttn, KENTUCKY.

IMPROVEMENT IN ARTlLLERY AND MINING BLAST ING. v

Specification forming partof Letters Patent no. 60,579,1dated December 18,1566.

To all whom it may concern:

Be-it known that LTAL. I. SHAFFNER, of Louisville, J efi'erson county, State of Kentucky, have discovered or invented a new and Improved Mode of Artillery Mining and Blasting; andI do hereby declare that the followingisa full and exact description thereof, reference being hadto the accompanying drawings, and to the letters of reference marked thereon.

. The'nature of my discovery or invention consists in the arrangements of combustible substances in such an glesand relative distances, so that when exploded simultaneously a greater disruption of matter will take place than when each charge is exploded singly, the same being an improvement upon my invention patented No. 51,67 4, dated December 19,1865. 7 To enable others skilled in the art to make and use my invention or discovery, 1 will proceed to describe the process employed by me. Practical blasting has for its object the demolition of solid matter, such, for example, as &c.; and that object has been accom plishedby drillingholes to a given depth,

depending upon the character of the explosive substance to be employed. For centuries gunpowder has been used. Within the past twenty years gun-cotton has been experimentally employed, excepting during the past five years it has been extensively and practically used in Wales, and, to some extent, in Austria, and

more recently by myself in the United States. During the past two years I have extensively erine) forblastingrock. With these substances I have, from time to time, practiceduponatheory suggested by me some twenty years ago, early after electricity became with me aprofessional study, namely, that, by combining the angles and positions of the drill-holes in rock, and explodingthem simultaneously, a greate." disruption of rock will take place than when each blast is exploded separately.

In 1855 I experimented in Finland, Russia,

for the purpose of blasting iron-ore, and though my electrical apparatus was imperfect, on ac' count of the fuse, yet I produced favorable results. In 1857 I repeated those experiments in Belgium, and practically attained success. At that time the batteries required for exploding many blasts at thesame instant were voltaic, and not practical for mining operations.

(commonly called nitro-glyc ed singly.

be put into the drill-hole will not Since then the magneto apparatuses have been sufficiently perfected to make the application of electricity for blasting purposes practical. I do not confine myself to any one kind of electrical generator, but can employ various kinds of apparatuses.

Havin'g satisfied myself that blasting could produceand efl'ect an increase disruption of rock,1 next proceeded to determineaformula to be'observed when thus blastin g, but the eii'ort was surrounded withmuch diliicultyh For example, the hardnessof the rock and V the quality of the explosive substance had to be relatively considered. un-- powder has an explosive force of thirteen thousand pounds per cubic inch gun-cotton,

' seventyeight thousand'pounds per cubic inch,

and nitroleum one hundred and sixty-ninethousand pounds per cubic inch. Powder differs accordingto quality of manufacture, the

gun-cotton according to condition of dryness,

but nitroleum does not seem to have any varying conditions of force. Thus stand the relative gases. Another diiiiculty has retarded the determination of a reliable formula, namely, the difi'erent areas occupied by the dilferent explosive substances, Practically applied, two ounces of gun-cotton occupy the same cubic area that three-quarters of a pound of gunpowder require; and nitroleum,of greater power than gun-cotton or gunpowder, as above mentioned, only occupies the space tilled by two ounces of gunpowder. nitroleum lies at the bottom of the drill-hole, while that of powder is distributed over about ten lineal inches. Having fully considered these different conditions, and made several.

thousands of blasts in rock, earth, and water, I have found that the following conditions, as rules, may be observed to attain the greatest success in blasting: The rock may be considered to be very hard,free of seams or slips; the drill-holes to be thirty inches deep, and blast- The cone of disruption will be equal to an equilateral triangle, with its side upon the surface of the rock, bisected by thedrillhole. In hard rock-such, for example, as mica and silex-the quantity of powder that can disrupt the rock, but the gas will blow outat the orifice. If the holebe reduced from thirty to twenty inches in depth, the powder may succeed. in

simultaneous The power of 2 came The simultaneous blasting produces the total disruption of the rock of the whole face of the heading, and, many times, below the bot tom of the holes. The gases act conjunctivel y, and disrupt at least doublcthe quantity of rock than be accomplished by separately discharging the blasts, as represented by Fig. l and 2.

lVhen applied to military purpose, for the demolition of earth, rock, or works simultaneous, blasting will prove eminently important. It will require a less number of explosive deposits, and a less number of combinations generally can efi'ect the demolition desired.

Having fully described my discovery or invention, and the mode of the application of the same sufiiciently clear to enable one skilled in the art to make and use the same, what I claim, and desire to secure by Letters Patent as in'yinvcntion or discovery, is-- The combination of blasts to be discharged simultaneously by electricity in such manner as will effect a conjunctive force ot'the respective charges, thereby increasing the disruption of matter beyond what can be obtained by separately discharging the said l lasts.

' TAL. l. SHAFFNER.

holes of the greater depth nitroleum can be successfully employed. Blasting singlyis represented by Figures 1 and 2.

Fig. l is the heading of a tunnel having at ertain angles and distances, each from the other, holes drilled into the rock horizontally. UjlQl] the surface these holes are at the angles of equilateral triangles. A, A &c., are the holes, and lines B B the triangular indications. .The circular lines 0 O 0 represent the circumference of the triangle brought to a circle from the center, where the drill-holcs bisect the exterior side. Fig. 2 represents a sectional View of Fig; 1; A A &e., the drill-holes charged, tamped, and with fuses. 13 13 850., are the sides of the equilateral triangles. l) D is the solid rock. The broken lines within the circles of Fig. 1, and within the triangles of Fig. 2, represent the broken rock after the blasts are dischargedseparately. The cone of force or of disruption is shown by Fig. 2; and the solid rock remaining is represented by D .l) D, &c., in each of the figures above described. Fig. 3 represents the heading of 'a tunnel with drillholes placed precisely as shown by Fig. 1. Fig. 4 representsa sectional view of Fig. 3, and is like Fig. 2. The blasting of Fig. 3 is supposed to be done by electricity, the whole being discharged-simultaneously. Fig. 4 shows the connection oi the electric'wires.

Witnesscs:

W. M. SHAFFNER, EDM. F, BROWN- 

